Methods of Fabricating Substrates

ABSTRACT

A method of fabricating a substrate includes forming spaced first features over a substrate. An alterable material is deposited over the spaced first features and the alterable material is altered with material from the spaced first features to form altered material on sidewalls of the spaced first features. A first material is deposited over the altered material, and is of some different composition from that of the altered material. The first material is etched to expose the altered material and spaced second features comprising the first material are formed on sidewalls of the altered material. Then, the altered material is etched from between the spaced second features and the spaced first features. The substrate is processed through a mask pattern comprising the spaced first features and the spaced second features. Other embodiments are disclosed.

RELATED PATENT DATA

This application is a continuation of U.S. patent application Ser. No.12/328,448, which was filed on Dec. 4, 2008, entitled Methods ofFabricating Substrates, listing Scott Sills, Gurtej S. Sandhu, and AntondeVilliers as inventions, and which is incorporated herein by reference.

TECHNICAL FIELD

Embodiments disclosed herein pertain to methods of fabricatingsubstrates, for example as may be used in the fabrication of integratedcircuitry.

BACKGROUND

Integrated circuits are typically formed on a semiconductor substratesuch as a silicon wafer or other semiconducting material. In general,layers of various materials which are either semiconducting, conductingor insulating are utilized to form the integrated circuits. By way ofexample, the various materials are doped, ion implanted, deposited,etched, grown, etc. using various processes. A continuing goal insemiconductor processing is to continue to strive to reduce the size ofindividual electronic components thereby enabling smaller and denserintegrated circuitry.

One technique for patterning and processing semiconductor substrates isphotolithography. Such includes deposition of a patternable maskinglayer commonly known as photoresist. Such materials can be processed tomodify their solubility in certain solvents, and are thereby readilyusable to form patterns on a substrate. For example, portions of aphotoresist layer can be exposed to actinic energy through openings in aradiation-patterning tool, such as a mask or reticle, to change thesolvent solubility of the exposed regions versus the unexposed regionscompared to the solubility in the as-deposited state. Thereafter, theexposed or unexposed regions can be removed, depending on the type ofphotoresist, thereby leaving a masking pattern of the photoresist on thesubstrate. Adjacent areas of the underlying substrate next to the maskedportions can be processed, for example by etching or ion implanting, toeffect the desired processing of the substrate adjacent the maskingmaterial. In certain instances, multiple different layers of photoresistand/or a combination of photoresists with non-radiation sensitivemasking materials are utilized.

The continual reduction in feature sizes places ever greater demands onthe techniques used to form the features. For example, photolithographyis commonly used to form patterned features, such as conductive lines. Aconcept commonly referred to as “pitch” can be used to describe thesizes of the features in conjunction with spaces immediately adjacentthereto. Pitch may be defined as the distance between an identical pointin two neighboring features of a repeating pattern in a straight linecross section, thereby including the maximum width of the feature andthe space to the next immediately adjacent feature. However, due tofactors such as optics and light or radiation wave length,photolithography techniques tend to have a minimum pitch below which aparticular photolithographic technique cannot reliably form features.Thus, minimum pitch of a photolithographic technique is an obstacle tocontinued feature size reduction using photolithography.

Pitch doubling or pitch multiplication is one proposed method forextending the capabilities of photolithographic techniques beyond theirminimum pitch. Such typically forms features narrower than minimumphotolithography resolution by depositing spacer-forming layers to havea lateral thickness which is less than that of the minimum capablephotolithographic feature size. The spacer-forming layers are commonlyanisotropically etched to form sub-lithographic features, and then thefeatures which were formed at the minimum photolithographic feature sizeare etched from the substrate.

Using such technique where pitch is actually halved, such reduction inpitch is conventionally referred to as pitch “doubling”. More generally,“pitch multiplication” encompasses increase in pitch of two or moretimes and also of fractional values other than integers. Thus,conventionally, “multiplication” of pitch by a certain factor actuallyinvolves reducing the pitch by that factor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagrammatic sectional view of a substrate in process inaccordance with an embodiment of the invention.

FIG. 2 is a view of the FIG. 1 substrate at a processing step prior tothat of FIG. 1.

FIG. 3 is a view of the FIG. 1 substrate at a processing step subsequentto that shown by FIG. 1.

FIG. 4 is a view of the FIG. 3 substrate at a processing step subsequentto that shown by FIG. 3.

FIG. 5 is a view of the FIG. 4 substrate at a processing step subsequentto that shown by FIG. 4.

FIG. 6 is a view of the FIG. 5 substrate at a processing step subsequentto that shown by FIG. 5.

FIG. 7 is a view of the FIG. 6 substrate at a processing step subsequentto that shown by FIG. 6.

FIG. 8 is a view of the FIG. 7 substrate at a processing step subsequentto that shown by FIG. 7.

FIG. 9 is a view of the FIG. 8 substrate at a processing step subsequentto that shown by FIG. 8.

FIG. 10 is a diagrammatic sectional view of another substrate in processin accordance with an embodiment of the invention.

FIG. 11 is a view of the FIG. 10 substrate at a processing stepsubsequent to that shown by FIG. 10.

FIG. 12 is a view of the FIG. 11 substrate at a processing stepsubsequent to that shown by FIG. 11.

FIG. 13 is a view of the FIG. 12 substrate at a processing stepsubsequent to that shown by FIG. 12.

FIG. 14 is a view of the FIG. 13 substrate at a processing stepsubsequent to that shown by FIG. 13.

FIG. 15 is a view of the FIG. 14 substrate at a processing stepsubsequent to that shown by FIG. 14.

FIG. 16 is a view of the FIG. 15 substrate at a processing stepsubsequent to that shown by FIG. 15.

FIG. 17 is a view of the FIG. 16 substrate at a processing stepsubsequent to that shown by FIG. 16.

FIG. 18 is a diagrammatic sectional view of another substrate in processin accordance with an embodiment of the invention.

FIG. 19 is a view of the FIG. 18 substrate at a processing stepsubsequent to that shown by FIG. 18.

FIG. 20 is a view of the FIG. 19 substrate at a processing stepsubsequent to that shown by FIG. 19.

FIG. 21 is a view of the FIG. 20 substrate at a processing stepsubsequent to that shown by FIG. 20.

FIG. 22 is a view of the FIG. 21 substrate at a processing stepsubsequent to that shown by FIG. 21.

FIG. 23 is a view of the FIG. 22 substrate at a processing stepsubsequent to that shown by FIG. 22.

FIG. 24 is a view of the FIG. 23 substrate at a processing stepsubsequent to that shown by FIG. 23.

FIG. 25 is a view of the FIG. 24 substrate at a processing stepsubsequent to that shown by FIG. 24.

FIG. 26 is a diagrammatic sectional view of another substrate in processin accordance with an embodiment of the invention.

FIG. 27 is a view of the FIG. 26 substrate at a processing stepsubsequent to that shown by FIG. 26.

FIG. 28 is a diagrammatic sectional view of another substrate in processin accordance with an embodiment of the invention.

FIG. 29 is a view of the FIG. 28 substrate at a processing stepsubsequent to that shown by FIG. 28.

FIG. 30 is a view of the FIG. 29 substrate at a processing stepsubsequent to that shown by FIG. 29.

FIG. 31 is a view of the FIG. 30 substrate at a processing stepsubsequent to that shown by FIG. 30.

FIG. 32 is a view of the FIG. 31 substrate at a processing stepsubsequent to that shown by FIG. 31.

FIG. 33 is a diagrammatic sectional view of another substrate in processin accordance with an embodiment of the invention.

FIG. 34 is a view of the FIG. 33 substrate at a processing stepsubsequent to that shown by FIG. 33.

FIG. 35 is a view of the FIG. 34 substrate at a processing stepsubsequent to that shown by FIG. 34.

FIG. 36 is a view of the FIG. 35 substrate at a processing stepsubsequent to that shown by FIG. 35.

FIG. 37 is a view of the FIG. 36 substrate at a processing stepsubsequent to that shown by FIG. 36.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

Some embodiments of methods of fabricating a substrate in accordancewith the invention, for example in forming integrated circuitry, aredescribed initially with reference to FIGS. 1-9. Referring to FIG. 1, asubstrate, for example a semiconductor substrate, is indicated generallywith reference numeral 10. In the context of this document, the term“semiconductor substrate” or “semiconductive substrate” is defined tomean any construction comprising semiconductive material, including, butnot limited to, bulk semiconductive materials such as a semiconductivewafer (either alone or in assemblies comprising other materialsthereon), and semiconductive material layers (either alone or inassemblies comprising other materials). The term “substrate” refers toany supporting structure, including, but not limited to, thesemiconductive substrates described above.

Substrate 10 is depicted as comprising material 12 which will ultimatelybe processed through a mask pattern formed thereover. Material 12 may behomogenous or non-homogenous, for example comprising multiple differentcomposition regions and/or layers. Spaced first features 14 have beenformed over substrate 12. Any suitable material is contemplated, andwhether homogenous or non-homogenous. In the context of this document,“spaced” refers to the lateral direction as opposed to vertically orotherwise. Spaced first features 14 may be patterned/formed by anyexisting or yet-to-be-developed manner, with photolithographicpatterning using photoresist (whether positive, negative or dual-toneresist resulting from single or multi-pattern lithography) being anexample. Further, spaced first features 14 may be formed by anytechnique described below. In one example, spaced first features 14 maybe in the form of elongated lines, for example running parallel oneanother over at least some portion of the substrate as would be viewedin a top-down view (not shown).

Further in one embodiment, spaced first features 14 may result fromlateral etching/trimming of wider features. For example, FIG. 2 depictssubstrate 10 at a processing step prior to that of FIG. 1. Such is shownas comprising spaced mask features 16, for example comprising,consisting essentially of, or consisting of photoresist, having beenfabricated over substrate 12 in a repeating pattern of a pitch “P”.Pitch P may be equal to, greater than, or less than the minimumphotolithographic resolution with which substrate 10 is fabricated.Regardless, spaced mask features 16 of FIG. 2 have been laterallytrimmed to reduce their respective widths to produce the exampleconstruction of FIG. 1 which comprises spaced first features 14. Suchmay be conducted by an isotropic etch which removes materialapproximately equally from the sides and tops of spaced mask features16. Alternately, chemistry and conditions may be used which tend to etchgreater material from the lateral sides of spaced mask features 16 thanfrom the respective tops. Alternately, chemistries and conditions may beused which tend to etch greater material from the tops of spaced maskfeatures 16 than from the lateral sides.

For example, the construction depicted by FIG. 1 can be derived byplasma etching the substrate of FIG. 2 within an inductively coupledreactor. Example etching parameters which will achieve essentiallyisotropic etching where material of spaced mask features 16 isphotoresist and/or other organic-comprising material are pressure fromabout 2 mTorr to about 50 mTorr, substrate temperature from about 0° C.to about 110° C., source power from about 150 watts to about 500 watts,and bias voltage at less than or equal to about 25 volts. An exampleetching gas is a combination of Cl₂ from about 20 sccm to about 100 sccmand O₂ from about 10 sccm to about 50 sccm. Where material of spacedmask features 16 comprises photoresist, such will isotropically etchmask features 16 at a rate from about 0.2 nanometer per second to about3 nanometers per second. While such an example etch is essentiallyisotropic, greater lateral etching of the spaced mask features willoccur as two sides are laterally exposed as compared to only a singleupper surface thereof.

If even more lateral etching is desired in comparison to verticaletching, example parameter ranges in an inductively coupled reactorinclude pressure from about 2 mTorr to about 20 mTorr, source power fromabout 150 watts to about 500 watts, bias voltage at less than or equalto about 25 volts, substrate temperature of from about 0° C. to about110° C., Cl₂ and/or HBr flow from about 20 sccm to about 100 sccm, O₂flow from about 5 sccm to about 20 sccm, and CF₄ flow from about 80 sccmto about 120 sccm.

It may be desired that the stated etching provide greater removal fromthe top of the spaced mask features than from the sides, for example toeither achieve equal elevation and width reduction or more elevationthan width reduction. The example parameters for achieving greater etchrate in the vertical direction as opposed to the lateral directioninclude pressure from about 2 mTorr to about 20 mTorr, temperature fromabout 0° C. to about 100° C., source power from about 150 watts to about300 watts, bias voltage at greater than or equal to about 200 volts, Cl₂and/or HBr flow from about 20 sccm to about 100 sccm, and O₂ flow fromabout 10 sccm to about 20 sccm.

The example FIGS. 1 and 2 embodiments depict the respective features ashaving equal shapes and widths relative one another in the depictedcross section, as well as equal spacing therebetween. Such is not,however, required in this or other embodiments.

Referring to FIG. 3, an alterable material 18 has been formed overspaced first features 14. Alterable material 18 interacts selectively oruniformly with certain materials with which it forms an interface.Alterable material 18 may be cast onto a pre-patterned surface (forexample as shown) and may be conformal or non-conformal. Casting viaspin-casting, dip-casting, drop-casting, or similar, are examples. Thealterable material will be altered with material from the spaced firstfeatures to form altered material on sidewalls of the spaced firstfeatures. The altered material may form spontaneously upon deposition ofthe alterable material, or be subsequently activated, for example viathermal, photonic, electronic, ionic (including acid-based chemistry)treatments, by way of examples only. Accordingly, the altering may occurduring deposition and/or after deposition. In one embodiment, noaltering occurs until after completion of the deposition of thealterable material. Further, the altering may be self-limiting in thecase of a limiting reagent or equilibrium conditions, or kineticallyarrested if reactants are in excess. Alterable material 18 may have aplanar outermost surface or a non-planar outermost surface, with anexample planar outermost surface 19 being depicted in FIG. 3. Alterablematerial 18 may or may not be homogenous.

Material 18 may be similar to a class of materials available fromClariant International, Ltd. as so-called “AZ R” materials, such as thematerials designated as AZ R200™, AZ R500™ and AZ R600™. The “AZ R”materials contain organic compositions which cross-link upon exposure toacid released from chemically-amplified resist. Accordingly for example,such materials constitute an example alterable material where materialof spaced first features 14 comprises chemically-amplified resist. Morespecifically, an “AZ R” material may be coated across photoresist, andsubsequently the resist may be baked at a temperature of from about 100°C. to about 120° C. to diffuse acid from the resist into the alterablematerial to form chemical cross-links within regions of the alterablematerial proximate the resist. Portions of the material adjacent theresist are thus selectively hardened relative to other portions ofmaterial that are not sufficiently proximate the resist. The materialmay then be exposed to conditions which selectively remove thenon-hardened portions relative to the hardened portions. Such removalmay be accomplished utilizing, for example, 10% isopropyl alcohol indeionized water, or a solution marketed as “SOLUTION C™” by ClariantInternational, Ltd. Processes utilizing the “AZ R” materials aresometimes considered examples of RELACS (Resolution EnhancementLithography Assisted by Chemical Shrink) processes.

A challenge with the “AZ R” materials is that they can be similar enoughin composition to photoresist that it may be difficult to selectivelyremove photoresist relative to hardened “AZ R” materials. In oneembodiment, alterable material 18 may be similar to the “AZ R” materialsin that it may comprise a similar or identical organic composition whichis altered (for instance, forms cross-links) upon exposure to one ormore substances (for instance, acid) released from material 20 overwhich material 18 lies when the substrate is baked. However, unlike “AZR” materials, material 18 may also contain one or more componentsdispersed in the organic composition which are provided to chemicallychange material 18 relative to material of features 14 (for example,photoresist in embodiments where material of features 14 may beselectively removed relative to material 18). Components which may bedispersed in an organic composition of a material 18 may include one ormore of titanium, carbon, fluorine, bromine, silicon and germanium. Anycarbon dispersed in the organic composition may be part of a carbidecompound so it is chemically different from bulk carbon of the organiccomposition. Any fluorine and/or bromine may be, for example, comprisedof hydrofluoric acid and hydrobromic acid. In some embodiments, thecomponents dispersed in an organic composition of a material 18 includeone or more inorganic components, such as, for example, silicon,germanium, metals (for instance, titanium, tungsten, platinum, etc.)and/or metal-containing compounds (for instance, metal nitride, metalsilicide, etc.). The component of material 18 that is similar to “AZ R”materials may be referred to as an “AZ R”-type composition. Accordingly,in some embodiments, alterable material 18 may be considered to have oneor more inorganic components dispersed in an organic “AZ R”-typecomposition. However, alterable material 18 may comprise other thanorganic and other than “AZ R”-type compositions, for example asexplained below.

Referring to FIG. 4, substrate 10 has been subjected to conditions whichcause inter-diffusion of materials 14 and 18 proximate spaced firstfeatures 14. Some substance of material 14 alters material 18 to formaltered material 20 proximate spaced first features 14. Accordingly, thealterable material is capable of being altered with material from thefirst spaced features to form altered material on sidewalls of thespaced first features, for example as shown in FIG. 4. In oneembodiment, the altering alters a portion of the alterable material 18adjacent each of spaced first features 14 to form altered material 20while leaving portions of the alterable material distal to spaced secondfeatures unaltered. FIG. 4 also depicts an embodiment wherein alteredmaterial 20 has been formed elevationally over spaced first features 14.Alterable material 20 may or may not be homogenous.

In some embodiments, material of spaced first features 14 compriseschemically-amplified photoresist, and the substance diffused from suchphotoresist which imparts the altering of material 18 is acid. The acidmay be caused to be released from photoresist by baking semiconductorsubstrate 10 at a temperature of at least about 100° C. The acid formscross-links with “AZ R”-type composition of material 18. The amount ofcross-linking, and the distance that the cross-linking spreads fromspaced features 14 may be adjusted by modifying one or both of bake timeand bake temperature.

As an additional example where spaced features 14 comprise silicon, anexample alterable material 18 is a refractory metal, such as titanium,to result in a reaction ultimately to form the altered material tocomprise a metal silicide. Such by way of example only is shown anddescribed in U.S. Patent Application Publication No. US 2007/0049030.Additional alterable materials depending at least in part upon thecomposition of the spaced second features are also of coursecontemplated, and whether existing or yet-to-be developed.

Referring to FIG. 5, and in one embodiment, un-reacted distal portionsof material 18 (not shown) which were not altered to form material 20have been removed, for example by etching, selectively relative toaltered material 20. Suitable chemistries and conditions may be selectedby the artisan depending upon composition of materials 18, 20 and 12.For example with respect to the “AZ R”-type compositions referred toabove, such removal may be accomplished utilizing isopropyl alcoholand/or SOLUTION C™ as discussed above. Where material 18 may compriseadditional components dispersed in an “AZ R”-type composition, suchcomponents may simply rinse away as the non-altered regions of material18 are removed. Alternately, such additional components may be removedwith solvents which remove the additional components. For instance, ifsilicon dioxide is utilized as a component of material 18, hydrofluoricacid may be utilized during removal of the non-altered regions ofmaterial 18 to ensure that the silicon dioxide of the non-alteredregions is removed in addition to the “AZ R”-type composition of thenon-altered regions.

Referring to FIG. 6, a first material 22 has been deposited over alteredmaterial 20, and is of some different composition from that of alteredmaterial 20. First material 22 may be of some different composition fromthat of spaced first features 14, or may be of the same composition asthat of spaced first features 14. Such may be conductive, semiconductiveor insulative, including any combination thereof. Examples includesilicon dioxide, silicon nitride, organic antireflective coatings,inorganic antireflective coatings, polysilicon, titanium or titaniumnitride, including any combination thereof.

Referring to FIG. 7, first material 22 has been etched to expose alteredmaterial 20 and spaced second features 24 have been formed whichcomprise first material 22 received on sidewalls of altered material 20.In one embodiment, no etch mask other than first material 22 is receivedover any of first features 14 during the etching of first material 22.In one embodiment, no etch mask other than first material 22 is receivedover the substrate during the etching of first material 22. For purposesof the continuing discussion, FIG. 7 depicts respective closest pairs 25of two immediately adjacent of second features 24 having a respectivespace between each two of a pair 25.

Referring to FIG. 8, altered material 20 (not shown) has been etchedfrom between spaced second features 24 and spaced first features 14.Chemistries and etching conditions depending upon materials may beselected by the artisan in conducting each of the FIGS. 7 and 8etchings. In one embodiment, no etch mask other than altered material 20is received over any of first features 14 during the etching of alteredmaterial 20. In one embodiment, no etch mask other than altered material20 is received over the substrate during the etching of altered material20. Regardless, FIG. 8 depicts an embodiment wherein second features 24are taller than first features 14. FIG. 8 depicts an example embodimentwhere a mask pattern 26 has been formed over substrate 12 and whichcomprises spaced first features 14 and spaced second features 24. Suchalso depicts an example embodiment wherein pairs 25 of immediatelyadjacent spaced second features 24 alternate with individual of spacedfirst features 14.

The above processing may be conducted, for example, to result in a pitchmultiplication which may or may not be sub-lithographic. Regardless, theFIGS. 1-8 embodiments depict mask pattern 26 (FIG. 8) having been formedto have a pitch which is one-third (an integer factor of 3) that ofpitch “P” of spaced mask features 16 in FIG. 2. Any degree of pitchreduction (including non-integer fractional reduction) in FIGS. 1-8, orotherwise, will of course be in large part determined on the degree ofany lateral trimming that may occur of spaced features (for example informing the substrate of FIG. 2 from that of FIG. 1) in combination withthickness of the deposited layers to produce the features and the spacesbetween features. For example, the thickness to which altered material20 is formed in FIG. 3 and its ultimate removal impacts the spacebetween adjacent features in the resultant mask pattern 26. Analogously,the deposition thickness of first material 22 in FIG. 6 in combinationwith the etching technique to produce the FIG. 7 construction impactsthe width of spaced second features 24. Further and regardless, some orall of spaced second features 24 and/or spaced first features 14 may befurther laterally trimmed after forming the FIG. 8 construction. Furtherby way of example, altered material 20 of FIG. 3 may be laterallytrimmed.

The mask pattern comprising the spaced second features and the spacedthird features is used to process the substrate received elevationallythere-below through such mask pattern. Such processing may constituteany existing or yet-to-be developed technique, with etching and/or ionimplanting being specific examples. FIG. 9 depicts one example with suchprocessing wherein mask pattern 26 has been used as an etch mask whileetching into material 12 of substrate 10.

Additional embodiments are next described with reference to FIGS. 10-17.FIG. 10 depicts an alternate embodiment substrate fragment 10 acorresponding in processing sequence to that of FIG. 4. Like numeralsfrom the first-described embodiments have been utilized whereappropriate, with construction differences being indicated with thesuffix “a” or with different numerals. While the suffix “a” indicatesdifferent construction, example material for such constructions is thesame as used in the above embodiments for the same numerals without thesuffix “a”. In FIG. 10, spaced first features 16 are received oversubstrate 12. Alterable material 18 a has been altered to form alteredmaterial 20 a of less thickness than that depicted in the embodiment ofFIG. 4.

Referring to FIG. 11, un-reacted distal portions of material 18 a (notshown) which were not altered to form material 20 a have been removed,for example by etching, selectively relative to altered material 20 a.

Referring to FIG. 12, altered material 20 a has been anisotropicallyetched to form spacer features 28 comprising altered material 20 a.

Referring to FIG. 13, first material 22 a has been deposited overaltered material 20 a.

Referring to FIG. 14, first material 22 a has been etched to exposealtered material 20 a of spacer features 28, and spaced second features24 a have been formed which comprise first material 22 a on sidewalls ofaltered material 20 a.

Referring to FIG. 15, altered material 20 a (not shown) of spacerfeatures 28 (not shown) has been etched from between spaced secondfeatures 24 a and spaced first features 16, thereby producing a maskpattern 26 a comprising spaced first features 16 and spaced secondfeatures 24 a. Substrate 12 may be processed through mask pattern 26 a.Regardless, FIG. 16 depicts alternate and/or additional processing toform a mask pattern 26 aa regardless of whether processing substratematerial 12 occurred with respect to mask pattern 26 a of the FIG. 15construction. Specifically, FIG. 16 depicts an example wherein spacedfirst features 16 of FIG. 15 have been laterally trimmed to reduce theirrespective widths, thereby forming spaced first features 16 a after theetching has occurred of altered material 20 a as depicted by theprocessing in going from FIGS. 14 to 15. Lateral trimming of maskfeatures 16 of the FIG. 2 embodiment might be conducted additionallyprior to deposition of alterable material 18. Further and regardless,one or both of spaced first features 16 a and spaced second features 24a in FIG. 16 might additionally be laterally trimmed independent andregardless of whether processing of substrate material 12 occurs usingmask pattern 26 aa as a mask. FIG. 16 depicts first features 16 a asbeing of the same width as first features 14 in FIGS. 1 and 8, althoughother shapes and sizes may result depending on the act and time oflaterally trimming.

Referring to FIG. 17, substrate 12 has been processed through maskpattern 26 aa. The example processing depicted in FIG. 17 is that of ionimplantation, forming implanted regions 30.

Additional embodiments of methods of fabricating a substrate are nextdescribed with reference to FIGS. 18-25 with respect to a substratefragment 10 b. Like numerals with respect to the above-describedembodiments are utilized where appropriate, with differences inconstruction being indicated with the suffix “b” or with differentnumerals. While the suffix “b” indicates different construction, examplematerial for such constructions is the same used in the aboveembodiments for the same numerals without the suffix “b”. FIG. 18depicts first features 16 b having been formed over substrate 12. Firstfeatures 14 from FIG. 1, or other construction features, mightalternately be formed. A material 29 of some different composition fromthat of spaced first features 16 b has been deposited. Examples includeany of those described above for first material 22. Material 29 may ormay not be homogenous.

Referring to FIG. 19, material 29 has been anisotropically etched toform spacers 34 on sidewalls of spaced first features 16 b.

Referring to FIG. 20, an alterable material 18 b has been deposited overanisotropically etched spacers 34.

Referring to FIG. 21, alterable material 18 b has been altered withmaterial from anisotropically etched spacers 34 to form altered material20 b on a sidewall of each anisotropically etched spacer 34. FIG. 21also depicts an embodiment wherein altered material 20 b has been formedelevationally over spacers 34.

Referring to FIG. 22, un-reacted distal portions of material 18 b (notshown) which were not altered to form altered material 20 b have beenremoved, for example by etching, selectively relative to alteredmaterial 20 b.

Referring to FIG. 23, altered material 20 b has been anisotropicallyetched and spaced third features 36 comprising altered material 20 bhave been formed.

Referring to FIG. 24, anisotropically etched spacers 34 (not shown) havebeen removed from substrate 10 b, thereby forming a mask pattern 26 bcomprising spaced first features 16 b and spaced third features 36.Substrate material 12 may be processed through mask pattern 26 b. Any ofspaced first features 16 b and spaced third features 34 may be laterallytrimmed prior to and/or after conducting such processing. FIG. 25depicts laterally trimming of spaced first features 16 b of FIG. 24 toform spaced first features 16 bb, and thereby a mask pattern 26 bb.Further by way of example only as described above, spaced first features16 b of FIG. 18 may have been or may be laterally trimmed prior todeposition of material 29 and formation of spacers 34. Additionally byway of example only, spaced first features 16 b might be laterallytrimmed both prior to forming anisotropically etched spacers 34 andafter removing such from the substrate.

FIGS. 26 and 27 depict an additional example embodiment substratefragment 10 c. Like numerals from the above-described embodiments havebeen utilized where appropriate, with construction differences beingindicated with the suffix “c” or with different numerals. While thesuffix “c” indicates different construction, example material for suchconstruction is the same as used in the above embodiments for the samenumerals without the suffix “c”. FIG. 26 depicts alternate constructionto that depicted by FIG. 23, and starting with a different substrateconstruction from that of FIG. 18 with respect to starting size andspacing of the spaced first features. In FIG. 26, spaced first features16 c have resulted from laterally trimming the initially formed maskfeatures prior to deposition of material 29 in FIG. 18, and which isdesignated as 29 c in FIG. 26. FIG. 27 depicts a mask pattern 26 c afterspacers 34 c (not shown in FIG. 27) have been removed.

Additional embodiments are next described with reference to FIGS. 28-32with respect to a substrate fragment 10 d. Like numerals from theabove-described embodiments have been utilized where appropriate, withconstruction differences being indicated with the suffix “d” or withdifferent numerals. While the suffix “d” indicates differentconstruction, example material for such construction is the same as usedin the above embodiments for the same numerals without the suffix “d”.Referring to FIG. 28, such depicts alternate processing to that shown byFIG. 6. Accordingly, the processing of FIGS. 1-5 has occurred whereinmaterial 18 may be considered as first alterable material which wasformed over spaced first features 14, and which was altered withmaterial from spaced first features 14 to form a first altered material20 on sidewalls of spaced first features 14. Such may be considered asforming spaced second features 50 (FIG. 28) comprising first alteredmaterial 20 and spaced first features 14. A second alterable material 52has been formed over spaced second features 50. Composition andattributes of second alterable material 52 may be the same as thatdescribed above for alterable material 18 and depending at least in parton composition of outermost regions of spaced second features 50.

Referring to FIG. 29, second alterable material 52 has been altered withfirst altered material 20 from spaced second features 50 to form secondaltered material 54 on sidewalls of spaced second features 50. In thedepicted example, such has also formed second altered material 54 to bereceived over tops of spaced second features 50. Composition andattributes of second altered material 54 are the same as that describedabove for altered material 20.

Referring to FIG. 30, unaltered second alterable material 52 (not shown)has been removed from the substrate selectively relative to secondaltered material 54.

Referring to FIG. 31, spaced third features 56 have been formed whichcomprise second altered material 54. An example technique for doing soincludes any substantially anisotropic etch, for example, conductedselectively relative to material 20 and material 12. In one embodiment,such may be conducted with no etch mask other than material 54 beingreceived over spaced second features 50. In one embodiment, such may beconducted with no etch mask other than material 54 being received overthe substrate.

Referring to FIG. 32, first altered material 20 (not shown) has beenetched from between spaced first features 14 and spaced third features56, thereby producing a mask pattern 26 d which comprises spaced firstfeatures 14 and spaced third features 56. In the depicted example,spaced third features 56 are taller than spaced first features 14.Substrate 12 is processed (not shown) through mask pattern 26 d, forexample as described in any of the above embodiments. Further, lateraltrimming may occur of one or both of spaced first features 14 and spacedthird features 56 prior to and/or after such processing. Likewise by wayof example only, spaced first features 14 may be laterally trimmed priorto depositing the first alterable material, and/or after the etching ofthe first altered material.

Additional embodiments are next described with reference to FIGS. 33-37with respect to a substrate fragment 10 e. Like numerals from theabove-described embodiments have been utilized where appropriate, withconstruction differences being indicated with the suffix “e” or withdifferent numerals. While the suffix “e” indicates differentconstruction, example material for such constructions is the same asused in the above embodiments for the same numerals without the suffix“e”. FIG. 33 depicts the substrate of FIG. 2 having spaced firstfeatures 16 formed over a substrate 12, and over which a first material60 has been deposited. First material 60 is of some differentcomposition from that of spaced first features 16. Example materialsinclude any of those described above for material 22. FIG. 33 alsodepicts an example wherein first material 60 is deposited to a thicknesswhich is less than that of spaced first features 16.

Referring to FIG. 34, a second material 62 has been deposited over firstmaterial 60, and is of some different composition from that of firstmaterial 60. Such may be of the same or different composition from thatof spaced first features 16. Example materials include any of thosedescribed above for material 22.

Referring to FIG. 35, second material 62 has been etched to expose firstmaterial 60, and two spaced second features 64 have been formed betweenadjacent spaced first features 16. Second features 64 are spaced fromfirst features 16 at least by first material 60 received therebetween.

Referring to FIG. 36, first material 60 has been etched from betweenspaced first features 16 and spaced second features 64, whereby a maskpattern 26 e has been formed. FIG. 36 depicts an example embodimentwherein spaced second features 64 are taller than spaced first features16.

Referring to FIG. 37, the width of first features 16 of FIG. 36 has beenlaterally trimmed, thereby forming a mask pattern 26 ee which comprisesspaced first features 16 e and spaced second features 64. FIGS. 33-37depict example embodiments where second features 64 are fabricated to beof substantially uniform maximum width. The lateral trimming in FIG. 37to produce the modified first features is also shown as producing asubstantial uniform maximum first feature width that is substantiallyequal to the substantially uniform maximum width of the second features64. Alternate constructions and/or additional processing are also ofcourse contemplated. Analogous processing may be shown and used with anyof the above-described embodiments.

In compliance with the statute, the subject matter disclosed herein hasbeen described in language more or less specific as to structural andmethodical features. It is to be understood, however, that the claimsare not limited to the specific features shown and described, since themeans herein disclosed comprise example embodiments. The claims are thusto be afforded full scope as literally worded, and to be appropriatelyinterpreted in accordance with the doctrine of equivalents.

1. A method of fabricating a substrate, comprising: forming spaced firstfeatures over a substrate, the spaced first features havingelevationally coincident bases; depositing an alterable material overthe spaced first features and altering the alterable material withmaterial from the spaced first features to form altered material onsidewalls of the spaced first features and having an elevationallyinnermost base that is elevationally coincident with the bases of thespaced first features; depositing a first material over the alteredmaterial, the first material being of some different composition fromthat of the altered material; etching the first material to expose thealtered material and forming spaced second features comprising the firstmaterial on sidewalls of the altered material; and after forming thespaced second features, etching the altered material from between thespaced second features and the spaced first features.
 2. The method ofclaim 1 wherein the spaced first features comprises photoresist.
 3. Themethod of claim 1 wherein forming the spaced first features comprisesforming spaced mask features followed by laterally trimming the spacedmask features to reduce their respective widths prior to depositing thealterable material.
 4. The method of claim 1 wherein forming the spacedfirst features comprises forming spaced mask features followed bylaterally trimming the spaced mask features to reduce their respectivewidths after the etching of the altered material.
 5. The method of claim1 wherein the first material is of some different composition from thatof the spaced first features.
 6. A method of fabricating a substrate,comprising: forming spaced first features over a substrate; depositingan alterable material over the spaced first features and altering thealterable material with material from the spaced first features to formaltered material on sidewalls of the spaced first features; depositing afirst material over the altered material, the first material being ofsome different composition from that of the altered material and thesame composition as that of the spaced first features; etching the firstmaterial to expose the altered material and forming spaced secondfeatures comprising the first material on sidewalls of the alteredmaterial; and after forming the spaced second features, etching thealtered material from between the spaced second features and the spacedfirst features.
 7. The method of claim 1 wherein the altering formsaltered material over tops of the spaced first features.
 8. The methodof claim 1 wherein the alterable material has a planar outermostsurface.
 9. The method of claim 1 wherein the alterable material has anon-planar outermost surface.
 10. The method of claim 1 wherein no etchmask other than the first material is received over any of the spacedfirst features during the etching of the first material.
 11. The methodof claim 10 wherein no etch mask is received anywhere over the substrateduring the etching of the first material.
 12. The method of claim 1wherein no etch mask other than the altered material is received overany of the spaced first features during the etching of the alteredmaterial.
 13. The method of claim 12 wherein no etch mask other than thealtered material is received over the substrate during the etching ofthe altered material.
 14. A method of fabricating a substrate,comprising: forming spaced first features over a substrate; depositingan alterable material over the spaced first features and altering thealterable material with material from the spaced first features to formaltered material on sidewalls of the spaced first features, the alteringoccurring during deposition of the alterable material; depositing afirst material over the altered material, the first material being ofsome different composition from that of the altered material; etchingthe first material to expose the altered material and forming spacedsecond features comprising the first material on sidewalls of thealtered material; and after forming the spaced second features, etchingthe altered material from between the spaced second features and thespaced first features.
 15. The method of claim 1 wherein the alteringoccurs after completion of the deposition of the alterable material. 16.The method of claim 1 wherein no altering occurs until after completionof the deposition of the alterable material.
 17. The method of claim 1wherein the altering alters a portion of the alterable material adjacenteach of the spaced first features to form the altered material whileleaving portions of the alterable material distal the spaced firstfeatures unaltered.
 18. A method of fabricating a substrate, comprising:forming spaced first features over a substrate; depositing an alterablematerial over the spaced first features and altering the alterablematerial with material from the spaced first features to form alteredmaterial on sidewalls of the spaced first features, the altering altersa portion of the alterable material adjacent each of the spaced firstfeatures to form the altered material while leaving portions of thealterable material distal the spaced first features unaltered;depositing a first material over the altered material, the firstmaterial being of some different composition from that of the alteredmaterial, etching the distal portions away selectively relative to thealtered material prior to the depositing of the first material; etchingthe first material to expose the altered material and forming spacedsecond features comprising the first material on sidewalls of thealtered material; and after forming the spaced second features, etchingthe altered material from between the spaced second features and thespaced first features.
 19. The method of claim 1 wherein the spacedfirst features comprise photoresist and the alterable material comprisesone or more inorganic components dispersed in an organic compositionthat is cross-linkable upon exposure to acid, wherein the material fromthe spaced first features includes acid, and the altering the alterablematerial comprises forming cross-links within the organic compositionupon exposure to the acid in the material from the spaced firstfeatures.
 20. The method of claim 19 wherein the one or more inorganiccomponents includes silicon.
 21. The method of claim 19 wherein the oneor more inorganic components includes metal.
 22. A method of forming apattern on a substrate, comprising: forming spaced first features over asubstrate; depositing an alterable material over the spaced firstfeatures and altering the alterable material with material from thespaced first features to form altered material on sidewalls of thespaced first features; depositing a first material over the alteredmaterial, the first material being of some different composition fromthat of the altered material; etching the first material to expose thealtered material and forming spaced second features comprising the firstmaterial on sidewalls of the altered material; and after forming thespaced second features, etching the altered material from between thespaced second features and the spaced first features, a resultantpattern after etching the altered material having pitch of about onethird that of the spaced first features.
 23. A method of fabricating asubstrate, comprising: forming spaced first features over a substrate;forming anisotropically etched spacers on sidewalls of the spaced firstfeatures; depositing an alterable material over the anisotropicallyetched spacers and altering the alterable material with material fromthe anisotropically etched spacers to form altered material on asidewall of each of the anisotropically etched spacers; and after thealtering, removing the anisotropically etched spacers from the substrateand forming spaced third features comprising the altered material. 24.The method of claim 23 comprising laterally trimming the spaced firstfeatures prior to said processing.
 25. The method of claim 24 whereinthe spaced first features are laterally trimmed prior to forming theanisotropically etched spacers.
 26. The method of claim 24 wherein thespaced first features are laterally trimmed after removing theanisotropically etched spacers from the substrate.
 27. The method ofclaim 24 wherein the spaced first features are laterally trimmed bothprior to forming the anisotropically etched spacers and after removingthe anisotropically etched spacers from the substrate.
 28. A method offabricating a substrate, comprising: forming spaced first features overa substrate; depositing a first alterable material over the spaced firstfeatures and altering the first alterable material with material fromthe spaced first features to form first altered material on sidewalls ofthe spaced first features; forming spaced second features comprising thefirst altered material and the spaced first features; depositing asecond alterable material over the spaced second features and alteringthe second alterable material with the first altered material from thespaced second features to form second altered material on sidewalls ofthe spaced second features; forming spaced third features comprising thesecond altered material; and etching the first altered material frombetween the spaced first features and the spaced third features.
 29. Themethod of claim 28 wherein the spaced first features comprisesphotoresist.
 30. The method of claim 29 wherein forming the spaced firstfeatures comprises forming spaced mask features followed by laterallytrimming the spaced masking features to reduce their respective widthsprior to depositing the first alterable material.
 31. The method ofclaim 29 wherein forming the spaced first features comprises formingspaced mask features followed by laterally trimming the spaced maskingfeatures to reduce their respective widths after the etching of thefirst altered material.
 32. The method of claim 28 wherein the spacedthird features are taller than the spaced first features.
 33. A methodof fabricating a substrate, comprising: forming spaced first featuresover a substrate; depositing a first material over the spaced firstfeatures which is of some different composition from that of the spacedfirst features, the first material being deposited to a thickness whichis less than that of the spaced first features; depositing a secondmaterial over the first material, the second material being of somedifferent composition from that of the first material; etching thesecond material to expose the first material and forming two spacedsecond features between adjacent spaced first features, the secondfeatures being spaced from the first features at least by first materialreceived therebetween, the spaced second features comprising the firstmaterial elevationally under an elevationally innermost base of thesecond material; etching the first material from between the spacedfirst features and the spaced second features; and after the etching ofthe first material, laterally trimming width of the first features. 34.The method of claim 33 wherein the first material is deposited to athickness which is less than that of the spaced first features.
 35. Themethod of claim 33 wherein the second features are of substantiallyuniform maximum width, the laterally trimming producing a substantiallyuniform maximum first feature width that is substantially equal to thesubstantially uniform maximum width of the second features.